1. Field of the Invention
The present invention relates generally to syringes. More particularly, the invention concerns a non-reusable syringe and needle of the character used to inject fluids into the body.
2. Discussion of the Prior Art
In recent times there has been an alarming increase in the spread of infectious diseases such as AIDS and hepatitis among drug users who reuse or share injection needles or syringes. The thrust of the present invention is to provide a syringe of novel design which can be used only once to inject fluids into the body.
In one form of the apparatus of the present invention, the handle which moves the plunger of the syringe from a first position to a second retracted position to draw fluid into the syringe from an external source is interconnected with the plunger by a special material which dissolves upon being exposed to fluid. The syringe can be actuated in air as many times as desired, but once filled with fluid and a pressure applied to depress the plunger to eject the fluid from the chamber through a needle, fluid enters a passageway in the plunger which exposes the special connector material to the fluid causing it to lose its structural integrity. If a refill of the syringe is attempted the handle simply pulls away from the plunger leaving the plunger in its depressed position. With the handle thus disconnected from the plunger, the syringe becomes useless since fluid from an external source cannot be drawn into the chamber for subsequent injection into the body. As will be discussed in greater detail hereinafter, the connecting medium or soluble material used to initially interconnect the handle and the plunger of the apparatus can be any type of biocompatible material which has structural integrity when dry, but which loses its structural integrity when exposed to a liquid.